Category Archives: Stem Cells

Stem cells in bone marrow need to produce hydrogen sulfide in order to properly multiply and form bone tissue, according to a new study from the Center for Craniofacial Molecular Biology at the Ostrow School of Dentistry.

Professor Songtao Shi, principal investigator on the project, said the presence of hydrogen sulfide produced by the cells governs the flow of calcium ions. The essential ions activate a chain of cellular signals that results in osteogenesis, or the creation of new bone tissue, and keeps the breakdown of old bone tissue at a proper level.

Conversely, having a hydrogen sulfide deficiency disrupted bone homeostasis and resulted in a condition similar to osteoporosis -- weakened, brittle bones -- in experimental mice. In humans, osteoporosis can cause serious problems such as bone fractures, mobility limitations and spinal problems; more than 52 million Americans have or are at risk for the disease.

However, Shi and his team demonstrated that the mice's condition could be rescued by administering small molecules that release hydrogen sulfide inside the body. The results indicate that a similar treatment may have potential to help human patients, Shi said.

"These results demonstrate hydrogen sulfide regulates bone marrow mesenchymal stem cells, and restoring hydrogen sulfide levels via non-toxic donors may provide treatments for diseases such as osteoporosis, which can arise from hydrogen sulfide deficiencies," Shi said.

Story Source:

The above story is based on materials provided by University of Southern California. The original article was written by Beth Newcomb. Note: Materials may be edited for content and length.

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Proper stem cell function requires hydrogen sulfide

However a team at the Research Institute for Stem Cell Research at CHA Health Systems in Los Angeles and the University of Seoul said they had achieved the same result with two men, one aged 35 and one 75.

"The proportion of diseases you can treat with lab-made tissue increases with age. So if you cant do this with adult cells it is of limited value, said Robert Lanza, co-author of the research which published in the journal Cell Stem Cell

The technique works by removing the nucleus from an unfertilised egg and replacing it with the nucleus of a skin cell. An electric shock causes the cells to begin dividing until they form a blastocyst a small ball of a few hundred cells.

In IVF it is a blastocyst which is implanted into the womb, but with this technique the cells would be harvested to be used to create other organs or tissues.

However, the breakthrough is likely to reignite the debate about the ethics of creating human embryos for medical purposes and the possible use of the same technique to produce cloned babies which is illegal in Britain.

Although the embryos created may not give rise to a human clone even if implanted in a womb, the prospect is now scientifically closer.

However scientists have been trying for years to clone monkeys and have yet to succeed.

Dr Lanza admitted that without strong regulations, the early embryos produced in therapeutic cloning could also be used for human reproductive cloning, although this would be unsafe and grossly unethical.

However, he said it was important for the future of regenerative medicine that research into therapeutic cloning should continue.

Reproductive biologist Shoukhrat Mitalipov of Oregon Health and Science University, who developed the technique last year said: "The advance here is showing that (nuclear transfer) looks like it will work with people of all ages.

Originally posted here:
Breakthrough in human cloning offers new transplant hope

By Estel Grace Masangkay

Researchers from the University of Michigan have discovered how mechanical forces in the environment influence stem cell growth and differentiation. The scientists arrived at the findings using a key ingredient in Silly Putty for their experiments.

Using an ultrafine carpet made out of polydimethylsiloxane, a key ingredient in Silly Putty, the scientists were able to coax stem cells to morph into working spinal cord cells. The Silly Putty component was made into a specially engineered growth system with microscopic posts. By varying the post height, the researchers were able to adjust the stiffness of the surface where the cells are made to grow.

Jianping Fu, assistant professor of mechanical engineering at the University of Michigan, said, This is extremely exciting. To realize promising clinical applications of human embryonic stem cells, we need a better culture system that can reliably produce more target cells that function well. Our approach is a big step in that direction, by using synthetic microengineered surfaces to control mechanical environmental signals.

Stem cells that were grown on tall, softer micropost carpets morphed into nerve cells faster and more often than those grown on stiffer surfaces. The colonies of spinal cord cells that grew on softer micropost carpets were also 10 times larger and four times more pure than those grown on rigid carpets or traditional plates.

The study is the first to directly link physical signals to human embryonic stem cells differentiation, in contrast to chemical signals. Professor Jianping Fu says the findings may lead to a more efficient way of guiding stem cells to differentiate and provide specialized therapies for diseases such Alzheimers, Huntingtons, Lou Gerhrigs disease, and others. Our work suggests that physical signals in the cell environment are important in neural patterning, a process where nerve cells become specialized for their specific functions based on their physical location in the body, said Professor Jianping.

The study from the University of Michigan was published online at Nature Materials this week.

Continued here:
U-M Researchers Use Silly Putty Ingredient To Study Stem Cells

Working esophagi from stem cells could be used to aid cancer patients in the future

Jason Goldman / Flickr Creative Commons

Doctors have implanted bio-engineered tracheas in patients, and researchers have experimented with growing bladders and kidneys. Now, another organ joins that list: the esophagus, which brings food and water to the stomach.

An international team of scientists working at Kuban State Medical University in Krasnodar, Russia, has built a working esophagus from stem cells, and implanted the organ into rats, the researchers say. The new esophagus functioned just as well as the rats' natural organs, said the researchers, who detailed their work today (April 15) in the journal Nature Communications.

Every year, about 18,000 people in the United States are diagnosed with esophageal cancer, and others suffer from congenital defects, or are injured after medical procedures or swallowing caustic materials. Many of these cases require surgery, which can involve taking a section of the small intestine or the stomach to replace part of the esophagus.

Unfortunately, this isn't always the best solution. Patients can suffer complications, and many still have trouble swallowing solid food after surgery. [5 Crazy Technologies That Are Revolutionizing Biotech]

Researchers led by Paolo Macchiarini of the Karolinska Institutet in Stockholm took a section of a rat's esophagus and removed the cells, leaving behind a scaffold of protein. Such "decellularization" is now a common technique for making structures for cells to latch onto when doing regenerative organ experiments.

To test whether the scaffold would be strong enough to stand up to repeated cycles of expansion and contraction, the scientists pumped air into it 10,000 times, allowing it to blow up and shrink.

The researchers then took stem cells called allogeneic mesenchymal stromal cells, which don't cause an immune reaction when implanted into tissue. Scientists placed these cells on the scaffold, allowing the esophagus to grow for three weeks.

They then implanted the esophagus into a rat, replacing up to 20 percent of its esophagus with the engineered version. They repeated this procedure in nine more rats.

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Lab-Grown Esophagi Implanted in Rats

Scientists have used steroids to enhance the performance of stem cells (Photo: Shutterstock)

Stem cells are highly promising for the treatment of everything from HIV to leukemia to baldness. In many cases, however, a great number of them must be used in order have a noticeable effect, which makes treatments impractical or expensive. Now, scientists at Harvard-affiliated Brigham and Women's Hospital have found that a smaller number of stem cells can still get the job done, if they're first hopped up on steroids.

The research was conducted by Doctors Jeffrey Karp and James Ankrum, the former of whom has also helped bring us painless medical tape for newborns, worm-inspired skin grafts, porcupine quill-inspired surgical patches, and superglue for holes in the heart.

The scientists started with ordinary mesenchymal stem cells, and treated them with glucocorticoid steroids. This caused the cells to produce an increased amount of indoleamine-2,3-dioxygenase (IDO), which is an anti-inflammatory agent. Since it was noted that the cells' IDO expression was highest when they were actually being exposed to the steroids, the scientists added steroid-containing microparticles to the cells, so that they could have access to the drugs at all times.

When the 'roided-up stem cells were then introduced to inflamed immune cells, they were found to reduce inflammation twice as effectively as unmodified mesenchymal stem cells.

"Our approach enables fine tuning of cell potency and control following transplantation, which could lead to more successful cell-based therapies," said Ankrum.

A paper on the research was recently published in the journal Scientific Reports.

Source: Brigham and Women's Hospital

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Scientists give stem cells a performance boost ... by putting them on steroids

Silly putty. We always knew it would fix the world's problems. Now, a team of mechanical engineers from the University of Michigan have proven it.

Taking polydimethylsiloxane, a type of silicone used in breast implants andthe key ingredient that gives Silly Putty its viscoelasticproperties, the team built a growth system to help human embryonic stem cells develop into motor neuron cells. Studies have been carried out in the past to demonstrate that different chemical properties are required to help coax the pluripotent cells into different types of adult cells. This study focussed on the physical, however -- the scaffolding upon which that maturation process takes place.

The scaffolding was made up of these polydimethylsiloxane threads -- the tiny Silly Putty threads are referred to as "microposts" in a paper describing the technique, and an array of these makes up the membrane for the cells to thrive on. The flexible quality of the material meant that when the team produced longer threads, the membrane became softer. This allowed the cells to develop far faster than if rigid, short ones were used.

Within 23 days, motor neurons being grown were ten times bigger than those matured in the lab using the usual methods or on the stiff membranes. Moreover, the cells that were produced exhibited many of the traits of their mature counterparts, including electrical properties and chemical signalling pathways. The paper published in Nature is actually named after that signalling pathway, Hippo/YAP, which is key to controlling organ size through the regulation of cell production and dispersion.

The hope is the method can speed up research into debilitating diseases, such as amyotrophic lateral sclerosis (ALS) where these key cells are lost.

"For ALS, discoveries like this provide tools for modelling disease in the laboratory and for developing cell-replacement therapies," commented Eva Feldman, a professor of Neurology at the University of Michigan's School of Medicine not involved in the study. Feldman is already picking up from the team's lead, using the approach to attempt to engineer motor neuron cells from patient's own cells.

Wired.co.uk has been in touch with Feldman and will update this article if we hear more about that project's progress.

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Silly putty silicone helps stem cells mature faster

Working esophaguses from stem cells could be used to aid cancer patients in the future

Jason Goldman / Flickr Creative Commons

Doctors have implanted bio-engineered tracheas in patients, and researchers have experimented with growing bladders and kidneys. Now, another organ joins that list: the esophagus, which brings food and water to the stomach.

An international team of scientists working at Kuban State Medical University in Krasnodar, Russia, has built a working esophagus from stem cells, and implanted the organ into rats, the researchers say. The new esophagus functioned just as well as the rats' natural organs, said the researchers, who detailed their work today (April 15) in the journal Nature Communications.

Every year, about 18,000 people in the United States are diagnosed with esophageal cancer, and others suffer from congenital defects, or are injured after medical procedures or swallowing caustic materials. Many of these cases require surgery, which can involve taking a section of the small intestine or the stomach to replace part of the esophagus.

Unfortunately, this isn't always the best solution. Patients can suffer complications, and many still have trouble swallowing solid food after surgery. [5 Crazy Technologies That Are Revolutionizing Biotech]

Researchers led by Paolo Macchiarini of the Karolinska Institutet in Stockholm took a section of a rat's esophagus and removed the cells, leaving behind a scaffold of protein. Such "decellularization" is now a common technique for making structures for cells to latch onto when doing regenerative organ experiments.

To test whether the scaffold would be strong enough to stand up to repeated cycles of expansion and contraction, the scientists pumped air into it 10,000 times, allowing it to blow up and shrink.

The researchers then took stem cells called allogeneic mesenchymal stromal cells, which don't cause an immune reaction when implanted into tissue. Scientists placed these cells on the scaffold, allowing the esophagus to grow for three weeks.

They then implanted the esophagus into a rat, replacing up to 20 percent of its esophagus with the engineered version. They repeated this procedure in nine more rats.

See the article here:
Lab-Grown Esophaguses Implanted in Rats

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New York, April 14 : The fluffiness of the medium of which human embryonic stem cells are growing affects the type of specialised cells they eventually become, a study shows.

The researchers coaxed human embryonic stem cells to turn into working spinal cord cells more efficiently by growing the cells on a soft, ultra fine carpet made of a key ingredient in Silly Putty.

"To realise promising clinical applications of human embryonic stem cells, we need a better culture system that can reliably produce more target cells that function well," said Jianping Fu, an assistant professor of mechanical engineering at University of Michigan.

"Our approach is a big step in that direction, by using synthetic micro-engineered surfaces to control mechanical environmental signals," he added.

This research is the first to directly link physical, as opposed to chemical, signals to human embryonic stem cell differentiation.

Differentiation is the process of the source cells morphing into the body's more than 200 cell types that become muscle, bone, nerves and organs.

Fu said the findings raise the possibility of a more efficient way to guide stem cells to differentiate and potentially provide therapies for diseases such as amyotrophic lateral sclerosis (Lou Gehrig's disease), Huntington's or Alzheimer's.

In the specially engineered growth system - the 'carpets' Fu and his colleagues designed - microscopic posts of the Silly Putty component polydimethylsiloxane serve as the threads.

The team found that stem cells they grew on softer carpets turned into nerve cells much faster and more often than those they grew on stiffer surfaces.

Read the rest here:
Stem cells grown on 'soft carpets' function better

PUBLIC RELEASE DATE:

13-Apr-2014

Contact: Nicole Casal Moore ncmoore@umich.edu 734-647-7087 University of Michigan

ANN ARBORThe sponginess of the environment where human embryonic stem cells are growing affects the type of specialized cells they eventually become, a University of Michigan study shows.

The researchers coaxed human embryonic stem cells to turn into working spinal cord cells more efficiently by growing the cells on a soft, utrafine carpet made of a key ingredient in Silly Putty. Their study is published online at Nature Materials on April 13.

This research is the first to directly link physical, as opposed to chemical, signals to human embryonic stem cell differentiation. Differentiation is the process of the source cells morphing into the body's more than 200 cell types that become muscle, bone, nerves and organs, for example.

Jianping Fu, U-M assistant professor of mechanical engineering, says the findings raise the possibility of a more efficient way to guide stem cells to differentiate and potentially provide therapies for diseases such as amyotrophic lateral sclerosis (Lou Gehrig's disease), Huntington's or Alzheimer's.

In the specially engineered growth systemthe 'carpets' Fu and his colleagues designedmicroscopic posts of the Silly Putty component polydimethylsiloxane serve as the threads. By varying the post height, the researchers can adjust the stiffness of the surface they grow cells on. Shorter posts are more rigidlike an industrial carpet. Taller ones are softermore plush.

The team found that stem cells they grew on the tall, softer micropost carpets turned into nerve cells much faster and more often than those they grew on the stiffer surfaces. After 23 days, the colonies of spinal cord cellsmotor neurons that control how muscles movethat grew on the softer micropost carpets were four times more pure and 10 times larger than those growing on either traditional plates or rigid carpets.

"This is extremely exciting," Fu said. "To realize promising clinical applications of human embryonic stem cells, we need a better culture system that can reliably produce more target cells that function well. Our approach is a big step in that direction, by using synthetic microengineered surfaces to control mechanical environmental signals."

The rest is here:
How a Silly Putty ingredient could advance stem cell therapies

April 14, 2014

Image Caption: University of Michigan researchers have found that mechanical forces in the environment of human embryonic stem cells influences how they differentiate, or morph into the body's different cell types. To arrive at the findings, they cultured the stem cells on ultrafine carpets made of microscopic posts of a key ingredient in Silly Putty. Credit: Ye Tao, Rose Anderson, Yubing Sun, and Jianping Fu

redOrbit Staff & Wire Reports Your Universe Online

An ingredient found in Silly Putty could help scientists more efficiently turn human embryonic stem cells into fully functional specialized cells, according to research published online Sunday in the journal Nature Materials.

In the study, researchers from the University of Michigan report how they were able to coax stem cells to turn into working spinal cord cells by growing them on a soft, extremely fine carpet in which the threads were created from polydimethylsiloxane, one component of the popular childrens toy.

According to the authors, the paper is the first to directly link physical signals to human embryonic stem cell differentiation, which is the process by which source cells morph into one of the bodys 200-plus other types of cells that go on to become muscles, bones, nerves or organs.

Furthermore, their research increases the possibility that scientists will be able to uncover a more efficient way to guide differentiation in stem cells, potentially resulting in new treatment options for Alzheimers disease, ALS, Huntingtons disease or similar conditions, assistant professor of mechanical engineering Jianping Fu and his colleagues explained in a statement.

This is extremely exciting, said Fu. To realize promising clinical applications of human embryonic stem cells, we need a better culture system that can reliably produce more target cells that function well. Our approach is a big step in that direction, by using synthetic microengineered surfaces to control mechanical environmental signals.

He and his University of Michigan colleagues designed a specially engineered growth system in which polydimethylsiloxane served as the threads, and they discovered that by varying the height of the posts, they were able to alter the stiffness of the surface upon which the cells were grown.

Shorter posts were more rigid, while the taller ones were softer. On the taller ones, the stem cells that were grown morphed into nerve cells more often and more quickly than they did on the shorter ones. After a period of three weeks and two days, colonies of spinal cord cells that grew on the softer micropost carpets were four times more pure and 10 times larger than those growing on rigid ones, the study authors noted.

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Silly Putty Ingredient Could Help Stem Cells Become Motor Neurons